Dust formation by supernovae and asymptotic giant branch stars

超新星和渐近巨分支星形成尘埃

• 批准号: ST/L003597/1
• 负责人: Mikako Matsuura
• 金额: $ 55.45万
• 依托单位: CARDIFF UNIVERSITY
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FL003597%2F1
• 关键词: Dust; formation; supernovae; asymptotic; giant

The main visible components of galaxies are stars and the interstellar medium (ISM). The ISM is filled with gas and dust, with dust taking only less than 1% of the total mass. Despite dust occupying such a small fraction of mass, its unique properties make it important for astronomy: dust can absorb and scatter star-light in ultra-violet and optical wavelengths and re-emit the absorbed energy in infrared and submillimetre wavelengths. This dust turns harmful UV photons to soft infrared and submillimetre light, thus protecting molecules, and providing a cradle for star formation. Empirically, it is known that galaxies that undergo extensive star-formation tend to be dusty, and emit more energy at infrared and submillimetre wavelengths. Yet, it is still unknown why these galaxies are so dusty in the first place.To form dust, atoms such as carbon, silicon, oxygen and iron, need to meet with other atoms. Consecutive meeting and bonding of atoms makes dust grow, ending up with a dust grain composed of hundreds and thousands of refractory elements. The reaction is efficient where gas is reasonably hot and dense, and where many refractory elements are available. The surroundings of asymptotic giant branch (AGB) stars, which are in the late stage of stellar evolution for 1-8 solar mass stars, provides an ideal place to make dust, as there is dense gas with some newly synthesised elements by the stars. Older textbooks usually describe the dust content of the ISM originating from AGB stars.A decade of advances in observational astronomy has challenged this traditional description of dust origin. Many high-redshift galaxies, located deep in space and observed less than one billion years old after the big bang, have been found to be much dustier than expected if dust is produced by AGB stars only. Hence, there must be some other objects to make a lot of dust within these galaxies.Theories have proposed that supernovae (SNe) can be an additional and significant dust source that makes galaxies dusty. SNe are the enormous explosion of massive stars at the end their lives, hence ejecting elements synthesised in stars into space. An explosion of SN 1987A was detected in the neighbouring galaxy, the Large Magellanic Cloud. The explosion was initially recorded in optical light, and neutrinos were also detected. Twenty-five years after I and colleagues found that the remnant of SN 1987A is filled with cold dust and molecules. Our observations with the Herschel Space Observatory and the Atacama Millemetre/submillemtre Array (ALMA) began to reveal that the supernova remnant has became cool, but is still dense enough for dust to form. The estimated mass of dust is about 0.5 solar mass, which is enough dust mass to make young galaxies dusty.A deficit of dust input has been suggested not only in high-redshift galaxies, but also in neighbouring galaxies. Of course, one possibility is that SNe are significant sources of dust in these galaxies as well. But an alternative view is that galaxies have acquired a large mass of dust in the past, but that they are now in a quiescent phase of dust formation, as there are not so many dust-forming stars at present. Combining new techniques introduced by the Spitzer and GAIA missions we can detangle these issues.My project aims to quantify the dust mass formed in supernovae and seeks to determine the physical and chemical process that lead to the formation in stars. In parallel, the project aims to elucidate what galaxy properties can have an impact on dust formation from stars, or vice-versa. The project will lead the way so we can build a full picture of the origin and evolution of dust in the Milky Way, nearby galaxies and high-redshift galaxies. The project will design the observing programs for future space missions JWST and SPICA. The outcome of this project has a potential to impact astrophysical processes involving dust, such as star-formation, stellar evolution and galaxy evolution.

星系的主要可见成分是恒星和星际介质(ISM)。ISM充满了气体和尘埃，尘埃只占总质量的不到1%。尽管尘埃只占质量的这么小一部分，但它的独特性质使其对天文学很重要：尘埃可以吸收和散射紫外线和光学波长的星光，并重新发射红外和亚毫米波长的吸收能量。这种尘埃将有害的紫外线光子转变为软红外和亚毫米级的光，从而保护分子，并为恒星的形成提供摇篮。从经验上讲，经过广泛恒星形成的星系往往是尘埃星系，在红外和亚毫米波长下释放出更多的能量。然而，我们仍然不知道为什么这些星系一开始会有如此多的尘埃。为了形成尘埃，碳、硅、氧和铁等原子需要与其他原子相遇。原子的连续相遇和结合会使尘埃生长，最终形成由成百上千种难熔元素组成的尘埃颗粒。当气体的温度和密度相当高，并且有许多难熔元素可用时，反应是有效的。对于质量为1-8个太阳质量的恒星，处于恒星演化后期的渐近巨星分支(AGB)恒星的周围是产生尘埃的理想场所，因为那里有稠密的气体和恒星新合成的一些元素。较旧的教科书通常描述来自AGB恒星的ISM的尘埃含量。十年来观测天文学的进步挑战了这种关于尘埃起源的传统描述。许多位于太空深处的高红移星系，在大爆炸后观察到的年龄不到10亿年，如果尘埃仅由AGB恒星产生，则被发现比预期的要灰暗得多。因此，一定有一些其他物体在这些星系中制造了大量的尘埃。理论提出，超新星(SNE)可能是一个额外的、重要的尘埃源，使星系成为尘埃。SNE是大质量恒星在其生命结束时的巨大爆炸，因此将恒星中合成的元素喷射到太空中。在邻近的大麦哲伦星云中发现了SN1987A的爆炸。爆炸最初是用光学记录的，也探测到了中微子。25年前，我和同事们发现SN1987A的残骸充满了冰冷的尘埃和分子。我们与赫歇尔空间天文台和阿塔卡马毫微米/亚毫微米阵列(ALMA)的观测开始揭示，超新星遗迹已经变冷，但密度仍然足够大，足以形成尘埃。估计的尘埃质量约为0.5个太阳质量，这足以让年轻星系产生尘埃。人们认为，不仅在高红移星系，而且在邻近的星系中，尘埃输入都是不足的。当然，一种可能性是SNE也是这些星系中尘埃的重要来源。但另一种观点认为，星系在过去获得了大量的尘埃，但它们现在处于尘埃形成的静止阶段，因为目前没有那么多形成尘埃的恒星。结合斯皮策和盖亚任务引入的新技术，我们可以解决这些问题。我的项目旨在量化超新星中形成的尘埃质量，并试图确定导致恒星形成的物理和化学过程。与此同时，该项目的目标是阐明哪些星系属性会对恒星尘埃的形成产生影响，反之亦然。该项目将起到带头作用，这样我们就可以全面了解银河系、附近星系和高红移星系中尘埃的起源和演化。该项目将为未来的JWST和Spica太空任务设计观测计划。该项目的成果有可能影响与尘埃有关的天体物理过程，如恒星形成、恒星演化和星系演化。

项目成果

Measuring the dust content and formation in SN 1987A using detailed radiative transfer modelling

使用详细的辐射传输模型测量 SN 1987A 中的灰尘含量和形成

• DOI: 10.1017/s1743921317004562
• 发表时间: 2017
• 期刊: Proceedings of the International Astronomical Union
• 作者: Baes M

A Catalogue of Galactic Supernova Remnants in the far-infrared: revealing ejecta dust in pulsar wind nebulae

远红外银河系超新星遗迹目录：揭示脉冲星风星云中的喷射尘埃

• DOI: 10.48550/arxiv.1811.00034
• 发表时间: 2018
• 作者: Chawner H

A complete catalogue of dusty supernova remnants in the Galactic plane

• DOI: 10.1093/mnras/staa221
• 发表时间: 2020-01
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: H. Chawner;H. Gomez;M. Matsuura;Matthew W. L. Smith;A. Papageorgiou;Jeonghee Rho;A. Noriega-Crespo;I. D. Looze;M. Barlow;P. Cigan;L. Dunne;Ken Marsh

Very Deep inside the SN 1987A Core Ejecta: Molecular Structures Seen in 3D

SN 1987A 核心喷射物的深处：以 3D 形式看到的分子结构

• DOI: 10.3847/2041-8213/aa784c
• 发表时间: 2017
• 期刊: The Astrophysical Journal
• 作者: Abellán F

A Galactic dust devil: far-infrared observations of the Tornado supernova remnant candidate

银河尘暴：对龙卷风超新星遗迹候选者的远红外观测

• DOI: 10.1093/mnras/staa2925
• 发表时间: 2020
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Chawner H